In the present investigation a reverse phase high performance liquid chromatographic method and a visible spectrophotometric method were developed for the quantitative determination of meropenem, a highly active antibiotic in powder for injection. The chromatographic analysis was carried out by reversed phase technique on an ultra sphere XL-ODS, 75mm x 4.6mm I.D.,5μm column with a mobile phase composed of ammonium acetate buffer of pH =4.0 and acetonitrile in the ratio 95:5 v/v, at a detection wavelength 298nm. In spectrophotometric method meropenem was reacted with oxidized form of 3-methyl 2-benzothia zolinone hydrazone (MBTH) in the presence of ferric chloride (Fe (III)) which forms an orange red colored chromogen giving absorption maximum at 600 nm. Linearity, precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ) were studied according to International conference Harmonization guidelines. The developed methods were found to be simple, sensitive, precise and accurate and can be used for the reliable quantization of meropenem in pure and pharmaceutical dosage form.